Chicago, IL-Based Cboe Global Markets 4Q 2017 Net Income Was $257 Mil, an Increase of a Spectacular 471% or Up By $212 Mil Over Its 4Q 2016 Net Income of $45 Mil ....................................................................................... $192 Mil or 91% of the $212 Mil 4Q 2017 Net Income Improvement From the 4Q 2016 Came From an Income Tax Benefit of $192 Mil Resulting From the Puzzling, Very Lucrative US Federal Income Tax Debt Forgiveness Feature in the US Trump Tax Bill